I couldn't find this posted earlier. I have a PC with dual monitors. My main monitor is connected via HDMI and Monitor 2 is connected with DVI off same graphics card. I have set to extend display, which works just fine.

However, sometimes I like to connect my work laptop via a VGA output to Monitor 1's VGA input. For the longest time, when I would change the input on Monitor 1 to VGA, my PC's desktop would migrate over to Monitor 2 (acting as the main monitor) and I could listen to music, surf the web etc. while my work laptop would display on Monitor 1 as intended.

Sometime in the past 3-6 months or so, when I change the input on Monitor 1 to the VGA input, Monitor 2 very briefly shows the migrated desktop (like it used to) but very, very quickly turn black as if the Monitor is searching for a single before going to sleep. The same thing occurs when I turn Monitor 1 off. Previously, whenever I turned Monitor 1 off or switched the input, my PC would just switch Monitor 2 as the main display and I could use Monitor 1 for my work laptop display and Monitor 2 as my PC's display.

I'm not sure why this is happening now.